/*
 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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 */

package javax.swing;

import java.util.*;
import java.io.Serializable;


/**
 * A simple implementation of <code>SpinnerModel</code> whose
 * values are defined by an array or a <code>List</code>.
 * For example to create a model defined by
 * an array of the names of the days of the week:
 * <pre>
 * String[] days = new DateFormatSymbols().getWeekdays();
 * SpinnerModel model = new SpinnerListModel(Arrays.asList(days).subList(1, 8));
 * </pre>
 * This class only stores a reference to the array or <code>List</code>
 * so if an element of the underlying sequence changes, it's up
 * to the application to notify the <code>ChangeListeners</code> by calling
 * <code>fireStateChanged</code>.
 * <p>
 * This model inherits a <code>ChangeListener</code>.
 * The <code>ChangeListener</code>s are notified whenever the
 * model's <code>value</code> or <code>list</code> properties changes.
 *
 * @author Hans Muller
 * @see JSpinner
 * @see SpinnerModel
 * @see AbstractSpinnerModel
 * @see SpinnerNumberModel
 * @see SpinnerDateModel
 * @since 1.4
 */
public class SpinnerListModel extends AbstractSpinnerModel implements Serializable {

  private List list;
  private int index;


  /**
   * Constructs a <code>SpinnerModel</code> whose sequence of
   * values is defined by the specified <code>List</code>.
   * The initial value (<i>current element</i>)
   * of the model will be <code>values.get(0)</code>.
   * If <code>values</code> is <code>null</code> or has zero
   * size, an <code>IllegalArugmentException</code> is thrown.
   *
   * @param values the sequence this model represents
   * @throws IllegalArgumentException if <code>values</code> is <code>null</code> or zero size
   */
  public SpinnerListModel(List<?> values) {
    if (values == null || values.size() == 0) {
      throw new IllegalArgumentException("SpinnerListModel(List) expects non-null non-empty List");
    }
    this.list = values;
    this.index = 0;
  }


  /**
   * Constructs a <code>SpinnerModel</code> whose sequence of values
   * is defined by the specified array.  The initial value of the model
   * will be <code>values[0]</code>.  If <code>values</code> is
   * <code>null</code> or has zero length, an
   * <code>IllegalArgumentException</code> is thrown.
   *
   * @param values the sequence this model represents
   * @throws IllegalArgumentException if <code>values</code> is <code>null</code> or zero length
   */
  public SpinnerListModel(Object[] values) {
    if (values == null || values.length == 0) {
      throw new IllegalArgumentException(
          "SpinnerListModel(Object[]) expects non-null non-empty Object[]");
    }
    this.list = Arrays.asList(values);
    this.index = 0;
  }


  /**
   * Constructs an effectively empty <code>SpinnerListModel</code>.
   * The model's list will contain a single
   * <code>"empty"</code> string element.
   */
  public SpinnerListModel() {
    this(new Object[]{"empty"});
  }


  /**
   * Returns the <code>List</code> that defines the sequence for this model.
   *
   * @return the value of the <code>list</code> property
   * @see #setList
   */
  public List<?> getList() {
    return list;
  }


  /**
   * Changes the list that defines this sequence and resets the index
   * of the models <code>value</code> to zero.  Note that <code>list</code>
   * is not copied, the model just stores a reference to it.
   * <p>
   * This method fires a <code>ChangeEvent</code> if <code>list</code> is
   * not equal to the current list.
   *
   * @param list the sequence that this model represents
   * @throws IllegalArgumentException if <code>list</code> is <code>null</code> or zero length
   * @see #getList
   */
  public void setList(List<?> list) {
    if ((list == null) || (list.size() == 0)) {
      throw new IllegalArgumentException("invalid list");
    }
    if (!list.equals(this.list)) {
      this.list = list;
      index = 0;
      fireStateChanged();
    }
  }


  /**
   * Returns the current element of the sequence.
   *
   * @return the <code>value</code> property
   * @see SpinnerModel#getValue
   * @see #setValue
   */
  public Object getValue() {
    return list.get(index);
  }


  /**
   * Changes the current element of the sequence and notifies
   * <code>ChangeListeners</code>.  If the specified
   * value is not equal to an element of the underlying sequence
   * then an <code>IllegalArgumentException</code> is thrown.
   * In the following example the <code>setValue</code> call
   * would cause an exception to be thrown:
   * <pre>
   * String[] values = {"one", "two", "free", "four"};
   * SpinnerModel model = new SpinnerListModel(values);
   * model.setValue("TWO");
   * </pre>
   *
   * @param elt the sequence element that will be model's current value
   * @throws IllegalArgumentException if the specified value isn't allowed
   * @see SpinnerModel#setValue
   * @see #getValue
   */
  public void setValue(Object elt) {
    int index = list.indexOf(elt);
    if (index == -1) {
      throw new IllegalArgumentException("invalid sequence element");
    } else if (index != this.index) {
      this.index = index;
      fireStateChanged();
    }
  }


  /**
   * Returns the next legal value of the underlying sequence or
   * <code>null</code> if value is already the last element.
   *
   * @return the next legal value of the underlying sequence or <code>null</code> if value is
   * already the last element
   * @see SpinnerModel#getNextValue
   * @see #getPreviousValue
   */
  public Object getNextValue() {
    return (index >= (list.size() - 1)) ? null : list.get(index + 1);
  }


  /**
   * Returns the previous element of the underlying sequence or
   * <code>null</code> if value is already the first element.
   *
   * @return the previous element of the underlying sequence or <code>null</code> if value is
   * already the first element
   * @see SpinnerModel#getPreviousValue
   * @see #getNextValue
   */
  public Object getPreviousValue() {
    return (index <= 0) ? null : list.get(index - 1);
  }


  /**
   * Returns the next object that starts with <code>substring</code>.
   *
   * @param substring the string to be matched
   * @return the match
   */
  Object findNextMatch(String substring) {
    int max = list.size();

    if (max == 0) {
      return null;
    }
    int counter = index;

    do {
      Object value = list.get(counter);
      String string = value.toString();

      if (string != null && string.startsWith(substring)) {
        return value;
      }
      counter = (counter + 1) % max;
    } while (counter != index);
    return null;
  }
}
